It seems like it should be easy to fake ADHD (attention deficit hyperactivity disorder) to get a prescription for Adderall, or more time on exams. Just read about the symptoms on the internet and then copy them in your appointment, right? But unfortunately for all you "malingerers" out there, several recent studies have determined which tests are best for weeding out ADHD fakers.

Undergraduates (n=44) randomly assigned to a control or a simulated malingerer condition and undergraduates with a valid diagnosis of ADHD (n=16). It was predicted that malingerers would successfully fake ADHD on the rating scale but not on the [performance test] for which they would overcompensate, scoring lower than all other groups.

The malingerer group was asked to read the following scenario to "encourage successful role-play":

Imagine yourself having trouble in school. Things aren't working out as you planned but your counselor's only advice is to buckle down. You want to get some help. You hear about adult ADHD on a television show. When talking to a friend about it, your friend tells you that you could get special accommodations from the university, like untimed tests and rescheduling of exams if two are given on the same day. Your friend adds that the stimulant medications that are generally prescribed have minimal side effects and that you can take the medicine only when you need it, just for school. You decide to read a book on ADHD. You find out that some ADHD adults even collect social security benefits. You conclude that you have enough of the symptoms. You convince yourself that you have ADHD. You go to the doctor and you really want to get help. In order to get these benefits, you need to convincingly act like a person who has ADHD.

As predicted, while the fakers did a good job lying about their ADHD-like symptoms on the behavior checklist, they overdid it on the performance test, getting worse scores than people with bona fide ADHD and thus marking them as malingerers:

Analyses indicated that the ADHD Behavior Rating Scale was successfully faked for childhood and current symptoms. [The performance test] could not be faked on 81% of its scales.

The performance of 31 undergraduates financially motivated and coached about ADHD via Internet-derived information was compared to that of 29 ADHD undergraduates following medication washout and 14 students not endorsing symptomatology. Results indicated malingerers readily produced ADHD-consistent profiles.

But although the fakers were easily able to produce ADHD-like symptoms, they couldn't pass tests designed specifically to spot people faking psychiatric problems:

All [symptom validity tests] demonstrated very high specificity for the ADHD condition and moderate sensitivity to faking, which translated into high positive predictive values at rising base rates of feigning.

The moral of the story? If you're going to try to fake ADHD, you'll also need to figure out how to distinguish yourself from other fakers. Or you could just spend that time studying.